Re: Support "Right Semi Join" plan shapes

Hi Alena Rybakina
For merge join
+ /*
+ * For now we do not support RIGHT_SEMI join in mergejoin.
+ */
+ if (jointype == JOIN_RIGHT_SEMI)
+ {
+ *mergejoin_allowed = false;
+ return NIL;
+ }
+
Tanks

On Wed, 6 Mar 2024 at 04:10, Alena Rybakina <lena(dot)ribackina(at)yandex(dot)ru>
wrote:

> To be honest, I didn't see it in the code, could you tell me where they
> are, please?
> On 05.03.2024 05:44, Richard Guo wrote:
>
>
> On Tue, Jan 30, 2024 at 2:51 PM Alena Rybakina <lena(dot)ribackina(at)yandex(dot)ru>
> wrote:
>
>> I have reviewed your patch and I think it is better to add an Assert for
>> JOIN_RIGHT_SEMI to the ExecMergeJoin and ExecNestLoop functions to
>> prevent the use of RIGHT_SEMI for these types of connections (NestedLoop
>> and MergeJoin).
>
>
> Hmm, I don't see why this is necessary. The planner should already
> guarantee that we won't have nestloops/mergejoins with right-semi joins.
>
> Thanks
> Richard
>
> --
> Regards,
> Alena Rybakina
> Postgres Professional: http://www.postgrespro.com
> The Russian Postgres Company
>
>